Abstract: Two employees of a power line contractor were driving a 2.4-meter length of copper ground rod into the ground at a substation. The employees drove the ground rod the first meter or so by hand. They then connected an air hammer to the rod. When the rod reached a depth of about 1.2 meters, it penetrated a concrete-encased 13.2-kilovolt (phase-to-phase) underground cable and caused an electrical fault. The ensuing electric arc burned both employees. Employee # 1 also received an electric shock that resulted in the amputation of his right little finger and three third-degree entry and exit burns on both hands. Employee # 2, who also received an electric shock but let go of the air hammer, sustained burns to his face, ears, hand, and lips. The two employees were hospitalized for their injuries. The employees, who had been wearing safety glasses, hard hats, safety boots, and leather gloves, had not been aware of the buried cable.